It is known that many comb copolymers may be used as wetting agents and dispersants, in particular for pigments. Comb copolymers are accordingly already known from the prior art which are obtained by reacting styrene/maleic anhydride copolymers (SMA resins) with polyalkylene oxide amines and polyalkylene oxide glycols. U.S. Pat. No. 6,310,143 describes comb copolymers produced in this manner which, in addition to imide structures, must mandatorily comprise amide and ester linkages of the side chain to the main chain, as a result of which these comb copolymers do not exhibit the hydrolysis resistance necessary for numerous applications as dispersants and wetting agents.
The same also applies to the comb copolymers known from U.S. Pat. No. 6,406,143 which do not comprise any imide groups, but instead only amide and ester linkages of the side chains with the main chain of styrene/maleic anhydride copolymer.
Against the background of this prior art, there was therefore a need to provide comb copolymers based on styrene/maleic anhydride copolymers having linear polyalkylene oxide polymers as side chains, which have not only outstanding hydrolysis resistance but also an outstanding wetting and dispersing effect and are thus ideally suitable for many areas of application, in particular for the production of pigment pastes and the use thereof in various products.